TAMPA, Fla. — Attacked from all sides by fellow Republicans, Texas Gov. Rick Perry softened his rhetoric if not his position on Social Security in a crackling presidential campaign debate Monday night. He fended off assaults on his record creating jobs and requiring the vaccination of schoolgirls against a cancer-causing sexually transmitted virus.

Across a fractious two-hour debate before a boisterous tea party crowd, the front-runner in opinion polls gave little ground and frequently jabbed back, particularly at his chief rival, former Massachusetts Gov. Mitt Romney.

But the criticism of Perry kept coming — from Romney on Social Security, from Texas Rep. Ron Paul saying the governor had raised taxes, from Rep. Michele Bachmann and former Sen. Rick Santorum assailing his executive order to require Texas schoolgirls to get a STD vaccine and more.

Perry bristled only once, when Bachmann seemed to suggest a connection between his executive order on the vaccinations and campaign contributions he received in Texas. "I'm offended," he said, if she had questioned his integrity.

Related stories

Monday night's faceoff marked the first time in a season of debates that internal Republican differences dominated rather than a common eagerness to unseat Democratic President Barack Obama.

Social Security was a key issue.

"A program that's been there 70 or 80 years, obviously we're not going to take that away," Perry said in the debate's opening moments as Romney pressed him on his earlier statements questioning the constitutionality of Social Security and calling it a Ponzi scheme.

The Texas governor counter-attacked quickly, accusing Romney of "trying to scare seniors" with his own comments on a program that tens of millions of Americans — including millions in the debate state of Florida alone — rely on for part or all of their retirement income.

The eight rivals shared a debate stage for the second time in less than a week, a pace that marked a quickening in the campaign to choose a challenger to President Barack Obama in 2012. The encounter was sponsored by tea party groups — the conservative voters who propelled the GOP to victory in the 2010 congressional elections, and by CNN.

In the debate's opening moments, Perry and Bachmann courted the support of tea party activists. Bachmann said she had "brought the voice of the tea party to the United States Congress as a founder of the tea party caucus."

Perry said he was glad to be at the debate with the Tea Party Express.

But it soon became clear that the presidential hopefuls were not only eager to court support from the most conservative voters but were anxious not to offend seniors and others who depend on Social Security and Medicare.

None of the three who have gotten the most support so far this year — Perry, Romney and Bachmann — said they favored repealing the prescription drug benefit in Medicare, which has a large unfunded liability. Paul, asked the same question, turned his answer to a call for ending the wars in Afghanistan and Iraq as ways to save money.

There was little time for niceties.

Within minutes of the debate's beginning,, Romney moved aggressively to press Perry on Social Security, saying the front-runner had previously called it a Ponzi Scheme, an absolute failure and unconstitutional.

Perry did not dispute the characterization. In his recent book he called the retirement income program an example of a federal initiative that is "violently tossing aside any respect for our founding principles of federalism and limited government."

Monday night, he said retirees and near-retirees are assured of receiving the benefits they've been promised — and should be — but changes are needed to make sure younger workers have any sort of benefit when they near retirement.

Romney wasn't satisfied with that, quoting others as saying the Texas governor's position on Social Security could spell defeat for the party as it tries to win the White House from Obama next year. Repeatedly, he pressed Perry to say whether he believes the program is unconstitutional. Just as insistently, Perry ducked.

Then he countered, quoting Romney as having said in his own book that if people did with their financing what had been done with Social Security receipts it would be a criminal offense.

"You've got to quote me correctly," Romney responded. "What I said was taking money out of the Social Security trust fund is criminal and it's wrong."

Social Security benefits are financed through a payroll tax that workers and their employers pay. According to the most recent independent forecasts, unless Congress enacts changes, benefits will have to be cut beginning in 2037.

Bachmann and Santorum were the aggressors when the topic turned to an executive order Perry signed in 2007 requiring the vaccination of Texas schoolgirls against STD.

Bachmann, whose candidacy surged and then fell back in the polls in less than a month, said that "to have innocent little 12-year-old girls be forced to have a government injection through an executive order is just flat out wrong. That should never be done. It's a violation of a liberty interest."

Perry said, as he has before, that it was a mistake to issue an executive order on the issue, but he defended wanting to have the vaccinations take effect.

Bachman didn't stop there. She said that "a big drug company that made millions of dollars because of this mandate" also had made a campaign contribution to Perry in Texas.

"The company was Merck, and it was a $5,000 contribution that I had received from them. I raise about $30 million. And if you're saying that I can be bought for $5,000, I'm offended," Perry retorted.

Immigration brought more criticism for Perry, who supports giving the children of illegal immigrants the same tuition breaks at state colleges and universities that other students receive.

"I'm proud we are having those individuals be contributing members of society," Perry said, adding that the policy was a state's rights issue.

The audience briefly booed the answer, while his opponents again pounced.

Perry and Romney also reprised an exchange they had last week in a debate in which each claimed the superior record of job creation as governor.

"I think Gov. Perry would agree that if you're dealt four aces, that doesn't make you a terrific poker player," Romney said.

"Well, I was going to say Mitt you were doing pretty good until you got to talking poker," Perry said, provoking laughter.

There was a brief letup in the crossfire when the subject of Federal Reserve Chairman Ben Bernanke — no favorite of Republicans — came up.

Perry stood behind his recent comments that it would be treasonous if the Fed were printing money for political reasons.

Romney let it pass, as did the others on stage.

Later, though, former Utah Gov. Jon Huntsman took aim at Perry's opposition to construction of a fence across the length of the border with Mexico.

"For Rick Perry to say that you can't secure the border is pretty much a treasonous comment," he said.
___

Associated Press writers Bruce Smith in South Carolina and Kasie Hunt in Washington contributed to this report.